Hi Doug; What form of heating are you planning for winter? I did not notice a rocket mass heater in any of your photo's?
Ha Ha sorry Doug I'm kind of a RMH fanatic... But seriously I see your going with the warm water barrel method.
They work great as long as you can keep them warm (don't count on the sun in winter) Let them get cold (not frozen just cold) and they will suck up any heat you have, leaving little for your plants.
Not all who wander are lost... J.R.R. Tolkien
Willie Smits: Village Based Permaculture Approaches in Indonesia (video)